Polyphenols improve non-alcoholic fatty liver disease via gut microbiota: A comprehensive review.

Kimia Mohammadhasani, Mohammad Vahedi Fard, Ali Mottaghi Moghaddam Shahri, Zahra Khorasanchi

Journal: Food science & nutrition 2024;12(8):5341-5356

PMID: 39139973

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Plain Language Summary

Non-alcoholic fatty liver disease (NAFLD) is a progressive liver condition linked to metabolic disorders. A well-balanced diet, such as the Mediterranean diet—rich in vegetables, fruits, legumes, and nuts—contains natural compounds with antioxidant and anti-inflammatory properties that may help prevent and manage NAFLD. This narrative review examined the effects of specific polyphenols, including chlorogenic acid (CGA), curcumin, green tea catechins, naringenin, quercetin, resveratrol, and sulforaphane, on NAFLD through their influence on gut microbiota (GM). The review shows that polyphenols support NAFLD management by improving gut microbiota composition. Gut microbiota imbalance (dysbiosis) contributes to NAFLD progression. Polyphenols promote beneficial bacteria (e.g., Lactobacillus and Bifidobacterium) and reduce harmful bacteria linked to NAFLD. Polyphenols reduce intestinal permeability ("leaky gut"), lowering endotoxin-induced liver inflammation. Polyphenols enhance short-chain fatty acid production, which supports liver health. Authors concluded that dietary supplementation with CGA, curcumin, green tea catechins, naringenin, quercetin, resveratrol, and sulforaphane may positively influence GM and intestinal barrier function, leading to potential benefits for NAFLD management.

Abstract

Polyphenols, natural micronutrients derived from plants, are valued for their anti-inflammatory and antioxidant properties. The escalating global prevalence of non-alcoholic fatty liver disease (NAFLD) underscores its status as a chronic progressive liver condition. Furthermore, the dysregulation of gut microbiota (GM) is implicated in the onset and progression of NAFLD through the actions of metabolites such as bile acids (BAs), lipopolysaccharide (LPS), choline, and short-chain fatty acids (SCFAs). Additionally, GM may influence the integrity of the intestinal barrier. This review aims to evaluate the potential effects of polyphenols on GM and intestinal barrier function, and their subsequent impact on NAFLD. We searched through a wide range of databases, such as Web of Science, PubMed, EMBASE, and Scopus to gather information for our non-systematic review of English literature. GM functions and composition can be regulated by polyphenols such as chlorogenic acid, curcumin, green tea catechins, naringenin, quercetin, resveratrol, and sulforaphane. Regulating GM composition improves NAFLD by alleviating inflammation, liver fat accumulation, and liver enzymes. Furthermore, it improves serum lipid profile and gut barrier integrity. All of these components affect NAFLD through the metabolites of GM, including SCFAs, choline, LPS, and BAs. Current evidence indicates that chlorogenic acid, resveratrol, quercetin, and curcumin can modulate GM, improving intestinal barrier integrity and positively impacting NAFLD. More studies are necessary to evaluate the safety and efficacy of naringenin, sulforaphane, and catechin.

Address: Department of Nutrition, Food Sciences and Clinical Biochemistry, School of Medicine, Social Determinants of Health Research Center Gonabad University of Medical Sciences Gonabad Iran.; International UNESCO Center for Health-Related Basic Sciences and Human Nutrition Mashhad University of Medical Sciences Mashhad Iran.; Department of Nutrition, School of Medicine Mashhad University of Medical Sciences Mashhad Iran.

DOI: 10.1002/fsn3.4178